Shoppers are being tipped to generate £4.5billion in sales this weekend as they go on a last-minute Christmas spending spree.

Some £2.8billion is expected to pass over the counters tomorrow alone, beating the record of £2.5billion set on December 17 last year.

Some stores have extended opening hours until midnight and two-thirds are running special offers and promotions, say accountants PricewaterhouseCoopers.

Prices have been cut by up to 80 per cent in Debenhams, 60 per cent in Argos and 50 per cent in John Lewis, while Marks & Spencer will open from midnight on Monday until at least 5pm.

Richard Dodd, of the British Retail Consortium, said: ‘We expect the biggest spending weekend ever. Christmas falling on a Tuesday means a lot of people beginning holidays have held off on major shopping until the last weekend.’

Retailers are preparing for what they hope will be the biggest shopping day of the year (Picture: PA)

Paul Lancaster, general manager of Lakeside shopping centre in Essex, said: ‘Saturday will be huge and probably our biggest day of the year.’

Another £2.4billion is expected to be rung through the tills on Boxing Day, when up to 9.8million shoppers hit the sales.

Figures released by the Office for National Statistics yesterday revealed sales rose by just 2.5 per cent in November – described as ‘below par’ by the CBI.

And there’s a warning for anyone heading to the sales. One in four shop assistants expects to have to break up fights between shoppers, a survey by website Quidco shows.